Need to start a serious discussion on all methods of actually locating sewer

Greetings to all, far and wide, on the 'Vine. I am likely to have some private locating jobs coming up on big college campuses, which will include the dreaded sewer locate. Thus, I would like to start a discussion on the finer nuances of locating sewer with anyone that has true knowledge of the subject.

So let's get some of the more obvious information out of the way. Sewer is typically regarded as the most difficult utility to locate for 2 different reasons.

1. Sewer is almost never metallic, 99.9% of the time. So take all of your electromagnetic instruments and throw them out the window (unless you have a duct rod...more on that later).

2. Thinking about reaching for the Ground Penetrating Radar (GPR)? It just so happens that sewer pipes are ALSO the DEEPEST utility on average. I have personally seen sewer mains 12 feet deep after popping off a manhole cover in the middle of a road that went through a college campus. In my experience using GPR, they usually don't see well below the 8 foot mark, at least not with a 350 MHZ antenna. No guarantees.

So you might think about reaching for a 500' duct rod and using your electromagnetic equipment on the duct rod as you snake it through the open manhole for the sewer. Problem is, it's astronomically unsanitary down there! All sorts of excrement. Ugh, gross. It would get all over the duct rod. How on earth would you keep the duct road in a sanitary condition?

And even if you used the duct rod, it would only find you the main line of the sewer, not where the individual services to the buildings tie into the main. The only way you could find those with a duct rod is if it had a camera on it as well, I would suppose. Or is that how you would normally use a camera?

Yeah so it seems like the devil's own luck to find sewer correctly. I would offer one last suggestion, though. Pop the manhole and get down on your knees and look into the depths of the hole without breaking the plane of the manhole itself (prevent inhaling poisonous gas and such).

Now look at where all the pipes tie into the common area of the man hole. Now drag your line of eyesight up from the hole, from where the pipe 10 feet down was, and look along the surface of the pavement. You could try to straight line the pipe with green paint, hopefully it goes to another manhole you could verify or into a building. As a last resort, of course. And wouldn't you have to block traffic for some of the manholes? They are usually smack dab in the middle of the road.

Also, has anyone ever had to politely explain to a client that due to scientific principles at work here, that your locating equipment just can't find some of the non-metallic lines? It's a tough conversation to have, isn't it? Any Winston Churchill type of oratory advice would be great to have here if anyone has any.

How about it? Any American sewer heroes out there want to chime in and lay down your two cents? We welcome anything constructive.

Re: Need to start a serious discussion on all methods of actually locating sewer

Really have to have a sewer camera system to do a good job. We stay at 12" and under, the laterals are 4 and 6 inch. Nice thing modern cameras you can light up the push cable at 33 and the sonde at 512 and do a dual trace. Really need a crawler camera for the mains and a seesnake for the smaller lines but they sell a 325ft seesnake and we hook it to the jetter and drag it down the line or pull it back when needed. Duct rodders we usually hook 2 of them up to the push camera and that works ok sometimes. As for the gunk your duct rodder really needs to be a dedicated one for sewers.

Re: Need to start a serious discussion on all methods of actually locating sewer

Sometimes you just have to tell the client you don't have the abllity to locate something. We sub our sewers that we can't line up manhole to manhole to a sewer inspection service. They have confined space equipment and the training to do it right. They jet and camera the sewer lines and are able to track they're camera. We take that info and transfer it to Google Earth so it can be located in the future. The bosses motto is do it right once so you don't have to sweat it later.

Re: Need to start a serious discussion on all methods of actually locating sewer

1) actually I'd say about 15-20 percent of sewers are metallic... they just are not conductive due to joints or material.

2) GPR is a viable option depending on your circumstances. Local Soil conditions, typical depths of sewers, and the antenna you are using. Typically you will have a mixed bag of results. We find it more cost effective to contract out those services currently.

I locate storm and sanitary lines in multiple locations. Where we are at, most mains can be located within a margin of reasonable accuracy by using line of sight. (MH to MH) It takes some practice, but 60% of our drainage locates, weather it's Storm or Sanitary can be completed by opening the MH's. (I think that the % could even be as high as 80%, but estimated low for arguments sake.) Knowing how the piping is installed helps as well. Knowing flow and how Clean Outs are installed helps with some of the direction changes. Unfortunately all this is still classed as "Unlocateable".

Cameras are the best option for figuring out what these lines are doing. However, using cameras are dependent on the condition of the pipes and weather your camera is able to view the pipe or if the pipe is clean enough to see anything.

What I used to tell customers was, "If it can locate, I can find it. The unlocateables are your biggest concern. I will mark these when I can 100% confirm where these lines are located. I will put indications of pipes on all features that I can not confirm their routing. If you want us to put a rodder or camera down the pipes, it will change the hourly rates and typically will extend the amount of time needed to perform the work. It may be cost effective to contract a plumbing company to perform this work since they are prepared for any seized cleanouts, debris in the lines, and any unforeseen issues that may arise."

I don't spurt all that information out at once, it usually takes place in the initial meeting to go over what they need me to do. I emphasize that I can do what ever they would like, but I also inform them of options that may be cheaper then paying us to open all the cleanouts just to find out the lines are filled with crap and we can't do anything but charge them for our attempts.

As for cleaning the camera and rodder. We wash ours after every use. Spray it with some disinfectant. Most importantly... Use gloves and get your Hepatitis shots.

Just remember, when you are talking to the customer. They don't want excuses on why you can't do it. They want honest and affordable options to get the work done. It may benefit you to see if your company recommends any particular company for the type of work you are looking at. We have a local company that does most of our large camera jobs. (I have a small push camera for most of the stuff we face on a regular basis.) This company only does camera work, but they are good at it. I've watched them build a Raft to float their large track camera down a 72" storm line that was half filled with water.

Let us know if this info helps or not. PM me if you want additional info.

Re: Need to start a serious discussion on all methods of actually locating sewer

Originally Posted by Cuda

Really have to have a sewer camera system to do a good job. We stay at 12" and under, the laterals are 4 and 6 inch. Nice thing modern cameras you can light up the push cable at 33 and the sonde at 512 and do a dual trace. Really need a crawler camera for the mains and a seesnake for the smaller lines but they sell a 325ft seesnake and we hook it to the jetter and drag it down the line or pull it back when needed. Duct rodders we usually hook 2 of them up to the push camera and that works ok sometimes. As for the gunk your duct rodder really needs to be a dedicated one for sewers.

X2 on what Cuda said, I'm a plumber and deal with this often, you really need to have a tractor cam and jetter to deal with the usual issues that arise..... the right equipment makes the job go smooth.....usually.....AND you provide a better picture to your client on what's really going on down there and where the lines run and tie in and Yada yada......

Re: Need to start a serious discussion on all methods of actually locating sewer

My first question is why do they need the sewer lines located, have they asked to have the entire system mapped out, I mean that's miles of shit pipe. 99% of my private locates, the client does not need to know the location/depth of sewers. They are either not working around it, or not working that deep.

When I do locate sewer I either use GPR (as you know it has its limitations) or I shove a traceable rodder down into it. I use 2" PVC sections with an elbow at the bottom that I shove into a sewer pipe. This was I can do it on my own, no entry required, the PVC helps get the rodder directly into the pipe and when your pushing the rodder into the pipe the force is against the PVC, works really well. I also stuck a golf ball on the end of the rodder, that helps it go down the pipe with ease. I bleach the rodder as I pull it back out then hose down the coil with bleach water and the soapy water. I put end caps on the PVC sections to keep the shit smell down in the van. Sewer sucks but its part of the job, for me at least. My only limitation with this system is the 300' of rodder I have.

Other options are renting a traceable camera/crawler or other GPR equipment. You would need a different antenna to see deeper.

Re: Need to start a serious discussion on all methods of actually locating sewer

I actually tried to locate an underground sewer line myself before. well, that did not go well. I called a phone number and reached Penhall. They advised me to dial #8-1-1 to reach a local public locator who did it at no-cost if the line was considered a public line. It was. I was so happy to have somebody came in and fixed what I did. I was so grateful that I reached Penhall who I later found out a private utility locating. I recommend that if you want utility locating service, dial #8-1-1 first to see if they can perform that for you. If not, go with Penhall- i think they are a reliable and honest locator. Here is their website: https://www.penhall.com/utility-locating/

Re: Need to start a serious discussion on all methods of actually locating sewer

Originally Posted by 13htran

I actually tried to locate an underground sewer line myself before. well, that did not go well. I called a phone number and reached Penhall. They advised me to dial #8-1-1 to reach a local public locator who did it at no-cost if the line was considered a public line. It was. I was so happy to have somebody came in and fixed what I did. I was so grateful that I reached Penhall who I later found out a private utility locating. I recommend that if you want utility locating service, dial #8-1-1 first to see if they can perform that for you. If not, go with Penhall- i think they are a reliable and honest locator. Here is their website:xxxxxxxxxxxx